Field of the Invention
The present invention relates to Coherent Diffractive Imaging with multiple, simultaneous, spatially distinct beams.
Discussion of Related Art
Coherent diffractive imaging (CDI), for example ptychography, is an emerging technique that enables wavelength- and diffraction-limited imaging without the need for refractive or reflective image forming optics. An object is illuminated and the resulting diffraction pattern is measured with a pixel detector. Then an image of the object is computationally reconstructed from the measured data using well known techniques such as those discussed in D. J. Batey, D. Claus, and J. M. Rodenburg, “Information multiplexing in ptychography,”Ultramicroscopy, vol. 138 C, pp. 13-21, December 2013 and P. Thibault and A. Menzel, “Reconstructing state mixtures from diffraction measurements,” Nature, vol. 494, no. 7435, pp. 68-71, February 2013.
In conventional CDI, one single beam illuminates the object to be imaged. More advanced CDI techniques are limited to spatially non-distinct beams. The traditional limitation that the illuminating radiation be spatially non-distinct produces a few disadvantages: 1) The total scanned area in the case of spatially non-distinct beams is smaller than in our technique 2) Spatially non-distinct beams necessarily encounter the same object during a scan hindering image reconstruction.
A need remains in the art for apparatus and methods for performing CDI with two or more spatially distinct beams.